Architecture
January 13, 1997
This is a closed-book exam. You have 1.5 hours to complete it. Answer all of the questions. Be concise in your answers. You will receive partial credit for partially correct answers, but extraneous remarks may count against you.
With approach A, the network adaptor contains 1 MByte of ``outboard'' memory that can be accessed (read/write) on a word-by-word basis across the I/O bus. The network adaptor can transmits outgoing messages from this memory, and can place incoming messages into predetermined regions of this memory at network speed.
With approach B, the network adaptor contains no memory. Outgoing messages are transmitted from main memory via direct memory access (DMA). Incoming messages are placed into predetermined regions of main memory via DMA. Assume that the DMA can proceed at network speed.
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